Pandoc installation from Cabal takes forever

[hafizhmakmur]

Hello,

I am trying to install a package using Cabal and it takes a very long time and I figure out that the bottleneck is at pandoc. So I tried to install pandoc by itself using simple cabal install pandoc-2.10.1 and so far it has taken more than 8 hours so I stopped it.

As can be seen here, I noted that the progress from [122 of 169] to [141 of 169] takes 6 hour by itself so far, and even after cancelling the cabal task it's still hogging memory. Is there a memory leak or flaw in the hackage package somehow?

[jgm]

On our CI machines the build usually takes half an hour or so with all dependencies.
But that is with 7 GB.

There's only so much we can do in pandoc itself to improve this. Partly it's a ghc problem.

One thing we can do is reduce the size of some of the larger modules. See
#6546
Since that issue is already tracking this problem, I'll close this one.

[jgm]

Btw, turning off optimizations should improve things quite a bit.
You can also try adding these ghc options, which we use in compiling (and can be found in cabal.project): -j +RTS -A64m -RTS.

[hafizhmakmur]

@jgm Thank you very much! The issue you linked looks relevant. Also I may try the options you mention.

[hafizhmakmur]

Dear Mr. @jgm , I have tried the -O0 option and -j +RTS -A64m -RTS but so far I found no luck in my 4GB device. So after analyzing the linked issue I realize that the problem starts at version 2.8 so I decided to install version 2.7.3 and along with it ghc-8.6.5 (with base-12.0.0 inside it). I'm looking forward for a new update that can be run with my mediocre computer! :D